dbs600

Hi all:

Debating between a IS250 AWD F-Sport and a IS350 AWD F-Sport. Primary reason for the purchase is fuel efficiency, but after driving each, I feel the 250 is a little slow.

Some q’s:

Is it true the 250 can take regular gas, but the 350 must use premium?

Real world, how much better is the 250 on fuel efficiency than the 350?

Very upsetting the F-Sport does not come with memory or cooled seats!

Is it true that removing the F-Sport badge would leave holes on the fender?

Otherwise, I thought AWD F-Sport’s come with 18" rims and All-Season tires. If so, I’ve seen MSRP option list print outs showing AWD F-Sport’s with “19" Split 5-spoke Alloy Wheels w/ Dark Graphite Finish w/ Summer Tires”. What’s going on? I don’t even see 19" wheels in the brochure or online, and no, it’s not a dealer installed option (cars haven’t even landed yet).

Last, is there a way to have the dealer contact the port to ensure the ugly port installed rear bumper applique is NOT installed?

Thanks!

Hoovey689

iTrader: (16)

Between the 250 and 350 it's only really a 2-3 mpg difference. So 100 more hp with the 350 makes far more sense to buy.

Where did you hear that? Both 250 and 350 are tuned for premium 91+ octane. Both have direct injection and a high engine compression ratio. Any car you could though regular in as cars are smart enough nowadays to adjust for knocking and pinging but you're affecting fuel economy (efficiency) and power. Stick with premium.

2-3 mpg. I'd rather take the tiny hit for the extra horses.

Europe gets ventilation and memory because they get leather. It's quite stupid that they won't even make it an OPTION for us. Some are willing to shell out the extra cash to get what we want..

Tiny little holes no passerby would even notice.

No 19" option on any IS that I know about. probably a typo

albino1

Just out of curiosity, if you don't care about actual performance, has anybody actually done the math and compared the price vs. MPG difference between 87 and 91? Is 87 so much more inefficient that the MPG goes down enough to lose money on the cost per gallon savings?

SonyHome

I've read some posters who own 2014 IS250 complain about lack of power. I have not had the chance to compare but I did test drove IS350 F Sport and it had plenty of power but there is also thread about MPG and some were getting bad MPG.

Also I'm not sure if you are aware but 2014 AWD models don't have the new 8 speed transmission or VGRS like the RWD models. Some other things that make me go besides the missing memory feature and cool seats.

Joe Z

iTrader: (10)

Not really sure that the Math matters...

If the motor calls for Premium or 91 in CA.. You put premium, plain and simple...

The $3 difference on a fill up is not worth the long term damage it will create by using 87.

~ Joe Z

Joe Z

iTrader: (10)

Yes... You will have 2 holes on each fender...

If the bumper appliqué is installed, you can ask for it to be removed.. It's just a clear bra film...

***********************************************************************************


2 locator pins on each badge, For proper alignment on an F-Sport Fender...







~ Joe Z

dbs600

Wow; thanks for the prompt replies everyone!!!

A few salespeople have said you can run the 250 on reg, but I guess that's true with every car these days. Otherwise, yes, my gut is telling me to go with the 350, but it's at least $50 more per mo... :|

Good question!

Hmm, lack of power on the 250, but poor MPG's on the 350. Argh.

Do you recall any threads in particular or should I search for same? Thanks.

Planning to lease, but yes, thanks for the insight!

Thanks for the descriptive pix, Joe. Sucks, why did they have to secure the badge with prongs!? Otherwise, I've asked one of the salespeople if the applique can be removed and they said yes, but that the bumper would need to be buffed out, as it doesn't come off easily; so I'd really rather them not apply it in the first place. :|

Haven't gotten around to asking if they can hold it back at port...

dbs600

Two more q's:

Why have I not seen ANY IS' with either the Mark Levinson audio sys or the power rear sunshade, both of which are listed in the brochure!?

Are these special order options I would need to place an order for?

Does anyone know how much they are?

Thanks again!

SonyHome

Here is the MPG thread.
https://www.clublexus.com/forums/is-...s-getting.html

You can order ML and Power Sunshade. I notice some regions don't offer certain features. For example if you change the Lexus.com to CA zip 94063 and go through the build there are a lot less options than you did the same thing using MN zip 55126. Not sure why some options on the IS are not available in some areas.

Hoovey689

iTrader: (16)

it's all regional. Dealership GM's in the western area for example get together and decide what they think guests want

keyframe13

This might be an interesting read for some.
http://www.cartalk.com/content/premium-vs-regular-0

Bass Mech

a long time ago someone did an experiment with different fuels in their car, actually ran the car out of gas to rid the tank of the octane rating on the previous fill up.
long story short..
he concluded that while the premium fuel is more expensive the lesser grade fuels got significantly less MPG to the point that running premium was a wash with the mid grade in terms of cost per mile.
in other words, the 91 got the best MPG while the 87 was almost as good but given the entire tank full the cost between the 2 was a wash.
so with that in mind just run the 91, its better for the engine and you get more HP out of it, less likely to get knock which will prematurely wear the connecting rod bearings, due to the pinging.
even though the ECU will retard ignition you really don't want the knock sensor to have to constantly adjust timing for low grade fuel.

Bass Mech

i wouldn't believe anything from that link..

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

if it pre-ignites there is no timing retard thats going to fix that because the plug is not what initially ignited the mixture.

the reason that higher octane gives better MPG is because there is a sweet spot usually just before 90 degrees rotation that yields the most torque to the crank shaft. since the power generated only lasts a fraction of a second during ignition it is critical you get the fuel burning and making max power at exactly the right time otherwise the energy is wasted.

think of this like the pedals on a bike, if you stand on the pedal at the very top of the crank shaft rotation your exerting very little rotational force to the crank. however if you put the same energy into the pedal at 90 degrees you get a lot more torque because the arm of the crank has the force applied at the farthest point perpendicular to the center line of the crank.

if you advance the timing too far not only will you waste energy near the top of the stroke, but all the fuel is spent before the crank reaches this sweet spot. if it is retarded it happens too late and the piston has past 90 degrees and is slowing down. think of the optimal timing visually, you want the expanding gasses from the power stroke almost chasing the piston down the bore. remember the pistons go up and down from 0 to about 70 mph and back to 0 every 1/2 revolution. the fuel has to ignite at just the right time to be able to push the piston down at exactly the right time.

if the fuel pre ignites because the octane rating is too low, a good deal of the energy is wasted because it was used before the piston really got moving during the power stroke.

i am a private pilot, and in airplanes we run 100 octane Low Lead in single engine piston aircraft. they use 100 octane because you need a reliable fuel that has no chance of pre ignition. when your 10,000 feet in the air you can't afford to have your fuel burning incorrectly or cause any pre mature wear on the engine that costs 35,000 bucks to rebuild. these engines are also air cooled and run much hotter temps than liquid cooled engines.
some of the engines run turbos or superchargers that effectively increase cylinder head pressure and increase compression. so to avoid getting the wrong gas, aviation for the most part uses 1 type of fuel that will work on any piston aircraft to prevent planes that need the higher rating from accidentally getting mixed up with the low grade fuel. (and Av gas runs about 6.00 per gallon!)
since airplanes run at a constant rpm while in steady cruise of about 2400-2500 rpm there is no need for timing advance, computers or even fuel injectors! the more crap you put on an engine the more stuff to fail and cause engine failure.
even the fuel injected planes use nothing more than a gear driven fuel pump driven off the back of the engine, to an adjustable fuel regulator that regulates fuel flow. then through a small splitter (manifold) and through brass tubes (like a small straw) with an orifice at the end and fuel is constantly sprayed directly into the intake manifold just before the intake valve.
since we change the A/F ratio while in flight and while changing altitude there no no need for a mechanical or electrically operated injector like on a car. that's just another item to clog or fail!
since the engine rarely changes rpm and you manually set the fuel ratio, why do you need a fuel injector in the automotive sense??

anyway back on topic, run the highest octane and quit *****in about the cost of fuel! the plane i fly burns about 12-15 gallons per hour at 6 bucks a gallon! thats about 90 bucks to go about 140 miles!

Bass Mech

by the way, there are actually only 2 grades of fuel at any pump, 91 and 85 if you use mid grade, the pump actually dispenses gas from both high and low grade at the same time, so the gas you get is a mix of the 2

dbs600

Some great info being dispensed guys; thanks!

Does anyone know if the F-Sport DOES NOT come with automatically dipping side-view mirrors when in Reverse (for parking)? Thought I came across something that said this in another thread, which I’m really not happy to hear; not a good combination with the low profile tires... :/